In an unusual move, the U.S. Department of Justice has filed a brief with the U.S. Supreme Court opposing a request for the high court to hear an appeal of a blockbuster American Express Co. antitrust case. The DOJ, under the Obama administration, had brought the case along with a group of states.

While it may not be unusual for one administration’s Justice Department to opt out of a case that was brought under a previous attorney general, it is rare for the DOJ to openly and actively oppose the granting of cert in its own case.